Apparatus for silencing pulsating gas streams and separating particles therefrom



Sept. 1943- A. s. CHIPLEY 2,329,101

APPARATUS FOR SILENCING PULSA'IING GAS STREAMS AND SEPARATING PARTICLESTHEREFROM Filed June 8, 1940 2 Sheets-Sheet 2 Patented Sept. 7, 1943APPARATUS FOR GAS STREAMS srmncmo rmsamo AND ssrana'rmo Paarrouzsrnrznnraou Allred S. Chiifles, Chicago, 111., assignor to BurgesaBattery Company, Chicago, Ill., a com-- ration of Delaware ApplicationJune 8, 1940, Serial No. 339,472

4 Claims. (Cl. 183-91) This invention relates to devices for removingparticles carried by the exhaust gases of internal combustion enginesand for silencing such exhaust gases.

The exhaust gases from all internal combustion engines carry particlesof carbon and the like some of which are incandescent and leave theexhaust system as sparks. The sparks present a fire hazard and otherparticles are generally undesirable since they settle in the vicinity ofthe exhaust outlet and give an unsightly appearance thereto. The exhaustgases from the Diesel engines are particularly heavily loaded with theforeign particles including oil droplets as well as solid particles.

So-called spark arr-esters have been in use for a number of years as asafeguard against the setting of fires due to theoperation of internalcombustion engines. Some of these devices operate to remove the largerparticles which are likely to remain incandescent a sumcient length ortime after leaving the exhaust system to cause damage, the smallerparticles being ignored, while other arresters have merely providedmeans for cooling these sparks prior to expulsion to the atmosphere.Some of these devices also functioned, to a greater or less extent, tosilence the exhaust gases In other cases a spark arrester was used inaddition to the silencer.

An object of the present invention is to provide a combined exhaust gascleaner and silencer which is very simple and inexpensive inconstruction yet eilicient in accomplishing the dual function of thedevice. A further object is to provide such a combined unit which doesnot depend upon tuned resonating chambers or similar acoustical devicesin accomplishing the silencing function and hence may be installed atany conven lent point in the exhaust system. A further object is toprovide a device of this character having exhaust gas cleaningefficiencie approaching 100 percent as required, for example, for Dieselengine installations in restricted neighborhoods and in marineinstallations, and at the same time operating at a minimum backpressure.

For convenience and clarity, and at the expense of strict accuracy, theterm spark arrest or" will be used herein to designate adevice forremoving particles from the exhaust gases, al-' though the device infact removes very line and cold particles, since spark arresting hasbeen the primary iunction of such a device and is accepted as thegeneric designation in the art. For similar reasons the term silencing"will be used as meaning the prevention of noise caused by the operationof the engine regardless of the actual mechanics of the operation. Theinvention herein described is believed to operate to prevent such noisesby smoothing the pulsating flow before the gases reach the atmospherethus preventing impact of the individual pulsations or slugs with theatmosphere with attendant percussions.

In the accompanyingv drawings:

Fig. 1 is a longitudinal, sectional view of a preferred form of theinvention taken at the line ll of Fig. 2 and Fig. 2 is a transverse,sectional view of the device of Fig. 1 taken at the line 2-2.

The embodiment of the invention illustrated in Fig. l is housed within acylindrical shell I. The unit is intended to be used in the verticalposition. The inlet-end or bottom member 2 and the outlet-end or topmember 3 are somewhat dished for strength and to prevent vibration, theformer being provided with an inlet opening 4 and the latter having anoutlet opening 5. These openings are at the center of the end members. Atransverse partition 8, preferably dished as shown and having a centralopening I, divides the space within the shell I into two chambers whichmay be designated for convenience as swirling or cleaning chamber 8 andsilencing chamber 8.

An inlet conduit l0 extends through the inlet opening 4, being providedwith flange I I for convenient connection to the exhaust pipe of theengine whose exhaust gases are to be cleaned and silenced. The end ofconduit it within the shell is also provided with a flange or collar I3.A number of vanes H are securely welded between flange l3 and a disc orplate l2 having approximatelythe same diameter as flange i3. Anysuitable number or vanes may be employed, six being illustrated in thedrawing. They are equally spaced apart leaving slots Ha between adjacentvanes for the passage of gases. These vanes are substantially plane,being curved, as illustrated in Fig. 2, only slightly for strength andto prevent vibration of thesemembers. They are tangentially arrangedwith respect to the conduit :0 whereby the gases with entrainedparticles passing through the slots l3 are directed substantiallytangentially from the inlet conduit toward the, lateral walls of theshell. The closure plate It is of suflicient diameter to completelycover the ends of vanes l4.

A lengthwise slot I5 is provided in a lateral wall of cleaning chamber 8for the passage of particles from the operating space within the chamberinto a zone of quiescence is within housing H. The bottom portion of thelatter forms a storage chamber I! intended to receive the foreignparticles from the zone or quiescence I6. Any suitable means is may beprovided for access to this chamber for removal of accumulated material.

An outlet conduit 20 extends through outlet opening 5 from flanged end2| outside of shell I into silencing chamber 9 to a point short ofpartition 6. A flange 22 having a lipped periphery 23 is preferablyprovided at the end of the outlet conduit within chamber 5. One or moreslots 24 are provided in the outlet conduit or this member may beotherwise perforated to a limited extent, as by means of round holes orshort slots.

A short tubular segment 25 extends toward the inlet end of the devicefrom partition 6 at opening 1, this segment also being flanged at 26.This tubular member is not essential in the construction of the unit butis advantageously used to increase its efliciency from both the cleaningand silencing standpoints.

The relative dimensions of this device are not critical but shouldpreferably be approximately as shown in'the drawing. The total area ofslots Ma should be approximately 1 to 4 times the cross-sectional areaof inlet conduit l0 and the total area of slot or slots 24 or otherequivalent apertures, if used, may be equal to from 30% to 100% of thecross-sectional area of the outlet conduit 20.

In the operation of the device illustrated-in Figs. 1 and 2, gasesentering the unit at the bottom (as indicated by the arrow) pass intothe cleaning chamber 8 through slots or passages Ma. The vanes l4 directthe gases together with the foreign particles carried by them toward thelateral walls of the shell I in a tangential direction with respect toinlet conduit as indicated by the broken line arrows in Fig. 2. Thegases turn and swirl about the axis of the shell, as indicated by thesolid line arrows in Fig. 2, but the particles, having greater specificmass and therefore inertia than the gases, tend to continue in thetangential direction toward the shell walls. The result is an immediateseparation of the large bull: of the particles from the gases, theparticles passing through slot and dropping down into the storage space[8 from which they may be removed periodically. Any fine particles whichare more readily carried by the swirling gases are separated bycentrifugal action. The particles collect in a layer adjacent the insidesurface of the shell walls and are eventually separated from the gasesby the edge of the shell at slot l5 facing the gases. As shown in Fig.2, slot I5 extends only approximately half way between the sides ofhousing ll, which construction more efiiciently operates to remove theforeign particles in the manner described.

The violently swirling gases move upwardly through cleaning chamber 8and pass into silencing chamber 9 through opening 1. Upon emerging intochamber 9, the gases immediately tend to flow radially as they spin sothat only a portion of the gases pass directly into outlet conduit 20.The larger portion of the gases, especially the gases flowing at peakspeeds due to the inertia of the exhaust gas slugs initially enteringthe device, pass into a snubbing space surrounding outlet conduit 20. Inthis space the velocity energy of the gases is partly spent and partlytransformed into static pressure which, in turn, is dissipated as thegases pass into the outlet conduit 20 through slots 24 in controlledvolumes. The relatively smoothly flowing stream of cleaned gases flowsto the atmosphere either directly from outlet conduit 20 or through atail pipe (not shown) connected to this conduit.

I claim:

1. A device for silencing a pulsating gas stream comprising an elongatedshell of circular transverse section having an inlet end and an outletend, a transverse partition having a central opening therein forming acleaning chamber at the inlet end and a silencing chamber at the outletend of said shell, deflecting means within said cleaning chamber andadjacent said inlet end of said shell adapted to cause all gasesentering said shell to swirl about the axis thereof, and an outletconduit extending from said outlet end of said shell into said silencingchamber and toward said central opening in said partition butterminating short thereof, said conduit having its walls apertured andbeing open at its and within said shell for direct communication withsaid opening in said partition.

2. A device in accordance with claim 1 and including a flanged tubularsegment extending from said partition at said opening therein towardsaid inlet end of said shell.

3. A device for silencing a pulsating gas stream comprising an elongatedshell having side walls of curved transverse section and an inlet endand an outlet end, a transverse partition having an opening thereinforming a cleaning chamber at the inlet end and a silencing chamber atthe outlet end of said shell, deflecting means within said cleaningchamber adjacent said inlet end of said shell adapted to cause all gasesentering said shell to swirl about the axis thereof, means at thelateral walls of said shell for trapping gasborne particles, and anoutlet conduit extending from said outlet end of said shell into saidsilencing chamber and toward said partition but terminating shortthereof, said conduit having its walls apertured and having its endwithin said shell open and in direct communication with said opening insaid partition.

4. A device in accordance with claim 3 in which the apertures in thewalls of the outlet conduit occupy an area equal to approximately 30% toof the cross sectional area of the outlet conduit.

ALFRED S. CHIPLEY.

